Un-cooled bolometer camera designs are very sophisticated, achieving high performance but at a high cost. Much of the cost of the camera is related to the cost of the array, the readout electronics, the addressing complementary metal oxide semiconductor (CMOS) in the array, the display electronics, and various other electronics systems. These features are all included to achieve high performance image, but at a high cost.
In such devices, infrared light from a target is imaged onto an array containing many pixels. This light, when illuminating a typical bolometer pixel, creates a change in the temperature of a “temperature sensing film” which can be fabricated in part from a vanadium oxide (VOx) material, such as vanadium dioxide (VO2).
Such a bolometer readout can be achieved by forming these pixels on top of CMOS electronics which can provide the row and column multiplexed addressing of a bias current which interrogates each pixel for a resistance change produced by the temperature increase caused by absorbed long wavelength infrared (LWIR) target radiation. The readout can be achieved via CMOS-bolometer integration.
The VOx material, however, may have an optical transition temperature (e.g., the temperature at which a change in the optical transmission of the VO2 material occurs) of 67 degrees Celsius. Accordingly, such devices having bolometer pixels fabricated from only a VO2 material (e.g., bolometer pixels that include only VO2 material) may be inoperable or difficult to operate in ambient environments, such as environments having a temperature near 20 degrees Celsius (e.g., room temperature).